<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            padding: 0;
        }
        .header{
            position: fixed;
           top: 0;
           left: 0;
           width: 100%;
           height: 70px;
           background-color: skyblue; 
        }
        .main {
            position: fixed;
            top: 70px;
            bottom:50px;
            left: 0;
            right:0;
            width: 100%;
            height: 100%;
            background-color: #096;
            overflow-y: auto;
        }

        .footer{
           position: fixed;
           bottom: 0;
           left: 0;
           width: 100%;
           height: 50px;
           background-color: pink;
            
        }

    </style>
</head>
<body>
    <div class="header">navBar</div>
    <div class="main">

        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>
        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>
        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>
        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>
        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>
        1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br> 1 <br>

    </div>
    <div class="footer">tabBar</div>
</body>
</html>